1. Field of the Invention
The present invention relates to an apparatus for determining whether or not a subject person has a status or constitution apt to develop deep-vein thrombosis occurring in a region of lower limb if he/she remains seated on a chair for many hours.
2. Prior Art
Recent years, a symptom called “economy-class syndrome” has been emphasized. This symptom may cause a blood circulation disorder such as thrombosis resultant from sitting on a narrow seat in an airplane for many hours without moving legs. In specific, a pumping action by muscle contraction around blood vessels would be no more effective, which could bring a body into a condition where the blood would be more likely to be clotted in a vein due to a jam (stagnation) of blood. Thus developed clot is referred to as a thrombus. It has been said that in a case where the thrombus has been produced particularly in a vein located in a deep region of a thigh (deep-vein thrombus), if the subject person in that condition starts to walk, then the thrombus will ride on the blood flow, which could block a vessel in a lung, developing a pulmonary thromboembolism and resulting in death of the subject person in the worst case. This symptom would not be developed exclusively in the airplane but the report says that there are also some cases of this symptom developed in a long time car driving or working in a seated position.
The symptom developed particularly in a region of lower limb is referred to as a deep-vein thrombosis in medical language, and it is considered that in one precautionary measure, moving muscles moderately to stimulate the blood circulation in legs can prevent this symptom but moving only an upper body without moving legs would not bring any effect. This means that the development of the deep-vein thrombosis can be prevented by moving legs to a moderate degree.
As pointed above, the deep-vein thrombosis in the lower limb region is considered to be a serious symptom involving in human lives, but there has been so far no effective method and/or apparatus provided for giving an objective determination whether or not the subject has the status that may easily develop this thrombosis with only the determination given conventionally according to a doctor's subjective point of view.
Further, in diagnosing on the pulmonary thromboembolism resultant from the development of the deep-vein thrombosis in the lower limb region, a blood test, an angiography in a lower limb, a blood flow measurement, a chest X-ray, an electrocardiography and so on have been used to determine an oxygen partial pressure and/or a carbon dioxide partial pressure. An engineer dedicated in operating those units for testing and/or measuring these items or values is required, which has made it not-easy to obtain the diagnosis.